. . . a Salt Trucker is a guy who no matter how many women he is talking to and/or is in the process of hitting on/flirting with goes out of his way to interrupt his friend's respective game normally by pushing his way into the conversation, snatching the buddy's perspective prey away to the bar and/or dance floor etc. This produces the effect of the protagonist or Salt-Trucker throwing "salt" on the smoothness of his friend's game much like salt is used to make slick roads drivable in winter hence the term "salt-trucker" . . . trust me, every group of male friends has one.
Salt-Truckers sometimes operate in stealth mode where they approach women under the guise of "helping you out" or acting as a "wingman." Normally this situation ends the next day when you say "What the hell?" and he says "Dude you so had your chance" and you say "When? That split second between you saying hello and her grinding all over you on the dance floor?"
I nearly went home with that girl last night but my Salt Trucker roommate swooped in and before I knew it he had drug her off, and this was after he had been making out with her friend all night.